Grinding mill



Ct. 15, 1929. C, E, NEEDHM 1,731,788

GRINDING MILL Filed 09's. 31, 1927 5 Sheets-Sheet 2 INVENTOR.

BY M @M L ATTORNEYS.

Oct. 15, 1929. c. E. Imaam-MM GRINDING MILL 5 Sheets-Sheet 3 Filed Oct. 3l, 1927 INVENTOR.

(Zar/'Zes Z/ZVedlza/rz l BY W #u M ATTORNEYS.

C- 15, 1929. c. E. NEEDHAM 1,731,733

GRINDING MILL Filed Oct. 31, 1927 5 Sheets-Sheet 4 l INVENTOR.

(kal/Zes EJVedlzam B Y my Y ATTORNEYS.

Oct. 15,l 1929. c. E. NEEDHAM @BINDING MILL Filed 0G17. 31, 1927 5 Sheets-Sheet 5 IN V EN TOR.

Zazzle-5E eedham 4 1/ @m1, ATTo'e/VEYS.

Patented Oct. 15., 1929 UNITED STATES Par orrrcn CHARLES NEEDHAM, or ALLENTowN, PENNSYLVANIA, AsSIGNoR To BETHLEHEM EOUNDRY a MACHINE COMPANY, A ooEPonATIoN on PENNSYLVANIA GRINDING MILL Application filed october 31, 1927.

This invention relates to grinding mills and more particularly to grinding mills having rolls for grinding' purposes which are forced outwardly by centrifugal force against the inner face of an annular die.

In the embodiment of the invention illustrated the grinding rolls are hung from a a support and are rotated by a vertical shaft driven by an overhead worm gear drive. The moving elements of the grinding mill are mounted upon a frame supported by the base which forms a main bearing, also serving as a support for the vertical shaft and the operating worm gearing.

The object of the invention is to improve the construction and operation of the grinding mill so that it is capable of withstanding the heavy strains of operation and to use a worm drive for the rolls which enables smoother operation than has heretofore been possible in grinding mills of this t pe.

yA further object of the invention is to provide a common integral casing for the overhead gearing and the worm drive with the bearings for the worm shaft within the main gear casing. v

A further object of the invention is the provision of eccentric bearing supports for the worm shaft to facilitate assembling and removal of the worm and worm gear.

A further obj ect of the invention is to provide an outboard steady bearing for the worm shaft arranged to permit eccentric movement of the worm 'shaft without dismantling the outboard bearing support.

A further object of the vinvention is to provide cooling means for the bearings and cooling coils in the lower portion of the main gear casing submerged in oil for cooling the oil.

Further objects'and advantages will be apparent from the following specification vand accompanying drawings in which Fig. 1 is a vertical section of a grinding millv showing one embodiment of the invenv tion.

Serial No. 229,898.

ing the worm out of mesh with the worm gear and in a position for removal.

Fig. 4 is an enlarged detailed sectional view of the worm shaft and its bearings.

Fig. 5 is an enlarged sectional view taken on line 5 5 of Fig. 4.

Fig. 6 is a side elevation of the thrust bearing seat for the end bearing of the worm shaft.

Fig. 7 is a side elevation of the worm' shaft eccentrics.

Fig. 8 is an enlarged sectional view taken on line 8 8 of Fig. 5.t

Fig. 9 is an enlarged sectional view taken on line 9 9 of Fig. 5. y

Fig. 10 is an enlargrd view of theeworm packing box taken on line 10-10 of Fig. 4.

Fig. 11 is an enlarged side elevation of the oil deflector for the worm bearing shown in Fig. 4.

Fig. 12 is an enlarged end elevation of the oil deflector for the worm bearing shown in Fig. 4.

Fig. 13 is an enlarged side elevation of the inner bearing nut for the end bearing of the worm shaft.

Fig. 14 is an enlarged end elevation of the inner bearing nut shown in Fig. 13.

Fig. 15 is an enlarged end elevation of the thrust bearing adapter of the worm shaft.

Fig. 16 is an enlarged side elevation of the thrust bearing adapter shown in Fig. 15, and

Fig. 17 is an enlarged sectional view of the thrust bearing bushing of the worm shaft.

In the embodiment of the invention disclosed in the drawings the grinding chamber 10 is formed by a lower base casting 11 upper annular member 12 which is supported from the base 11 and connecting annular member 13 the general arrangement being such as is customarily employed in grinding mills of this type. Supported within the base 11 is a I'iXed annular die 14 adapted to be engaged by a plurality of grinding rolls 15 which are equally spaced above the vertical axis. The grinding rolls 15 are rotatably mounted on spindles 16 which are pivoted to bearings 17 mounted upon a rotatable plate 18 attached to and rotated by the vertical shaft, 19. The rotatable plate 18 is provided with openings 2O adapted to receive material to be ground from a hopper 21 and deliver the material to the grinding chamber 10 in front of the rolls 15 through chutes 22. The vertical shaft 19 is adapted to be rotated by a-worm gear 23 keyed and clamped to the upper end of theshaft and a worm 24 keyed to outwardly extending shaft 25 connected to a motor through flexible connection 26. .The shafts 19 and 25, worm gear 23 and worm 24 are housed and supported in a frame comprising two supports 27 and an overhead connecting structure 28.

The flexible connection 26 comprises a flange 29 keyed to shaft 25 having a series of pins 30 extendingoutwardly therefrom and a flange 31 attached to the driving shaft of a motor having a series of pins 32 extending outwardly therefrom. An endless belt 33 is 'interwoven between the pins 30 and 32 connecting the flanges 29 and 31 forming a Vdriving connection between amotorshaft (not shown) and the worm shaft 25. The overhead structure 28 has an integral section 34 which forms an oil receptacle and a housing enclosing the worm gear 23 with a cover 35. One side of the section 34 is extended forming an integral straight section 36 for the worm shaft bearings. An endless water coil 37 for cooling the oil within section 34 is `attached to the bottom of section 34' by clamping members 38 bolted to section 34 below the worm gear 23 having an inlet 39 and an outlet 40 connected to any desired water supply. 1ntegral with section 34 is a bearing support 41 for the main vshaft bearing.

The worml shaft 25 is mounted in water cooled eccentric bearing 42 and eccentric bearing 43 which when rotated will remove the worm 24 from in mesh with the worm gear 23 so that the worm shaft can be removed longitudinally as shown in Fig. 3. rlhe concentric outboard bearing 44 isA mounted on an outwardly extending arm 45 secured to the frame structure 28 and leg 27 by means of bolts 46 and 47. The bolt 47 passes through a longitudinal slot 48 so that the arm 45 can be moved longitudinally outward when shaft 25 is rotated on its eccentric bearing 42 and 43 the bolt 46 being removed for this purpose.

The arm 45 is also provided with'longitudinal slots 49 so that the ywater pipes 39 and 40 will not interfere with'its longitudinal movement. It will be readily seen that the assembled outboard bearing 44 does not have to be removed indisassembling the worm drive.

The bearing` 42 and bearing .43 Vare provided with eocentrics 50 having' water lcooling passages. The water passages are longitudinal of the eccentrics having two branches namely y an inlet 52 and an outlet 53 connected by-a section 54 so that the water enters the bearings, circulates through them in two directions and passes out again. 'Concentric ing 85 with the shaft 25 and within the eccentric 59 is the rollway 55 containing roller bearings 56. Adjacent to the rollway of the bearing 42 is the oil deflector 57 clamped to the shaft 25 by means of nut 58 threaded to tapered section 59 which is slotted at 60 for clamping to shaft 25. Oil slots or passages 61 in the deflector upon rotation of the shaft 25 force the oil taken into eccentric 50 through oil passage 62 toward the rollway 55 as shown in Fig. 4. A worm shaft packing box 63 of the same diameter as the eccentric 50 is held in position by bolts 64 abutting the eccentric having holes 65 and 66 communicating with inlet and outlet 52 and 53. Within the worm shaft packing box `and bolted thereto by boltr67 is a worm shaft packing gland 68. The 'bearing 42 is continually cooled by circulation of water and the oil is continually circulated therethrough by deilector 57. V

The end bearing 43 is provided with identically the same eccentric 50 and rollway 55 as bearing 42 but is further provided with a thrust bearing. Spaced from the rollway 55 by bearing spacer 69 is the inner bearing nut 70 threaded to shaftc25 and keyed thereto by key 71Vpassing through the shaft. This nut is also rovided with slots or oil passages 72 for dei ecting the oil toward the rollway 55.

rllhe thrust bearing seat 7 37 the eccentric 50,V i

thrust bearing chamber'74 and cover plate 75 are held in assembled relation and secured to section 36 by means of bolts 76.

The thrust bearing seat 73 is provided with a radial water assaofe 77 communicating with Y longitudinal water passage 78 leading Vinto water passage inlet 52 of the eccentric 50. A longitudinal water passage 79 passes through the thrust bearing seat 73 communicating at one end with the outlet passage 5 3 of eccentricf 50 and at its opposite end with longitudinal passage V8O of thrust bearing chamber 74 leading to opening 81. The water passes out through passage 82 of the thrust bearing chamber through the eccentric .50, thrust bearing seat 73 land thrust bearing chamber 74. `With in the thrust bearing chamber is a thrust 74 completing the circulating Y Vpassages which, provide a water circulation bearing`83 having an adapter 84, a busliand bearings 86. TheV bearings 86, bushing V85 and adapterV 84A are held in assembled relation by a `nut 87 threaded tothe end of shaft 25 with awasher 88 between itand the end plate 75.V The adapter 84 is provided with radially extend- Ving fins 89 which rotate withinthe oil in chamber 74. These fins have oil passages 90 for the oil picked up by the fins communieating with longitudinalA oil' passages91.

The oil passages'91 communicate'with oil passages 92 within the bushing 85 which at intervals are connected with oil holes 93 leading directly to the bearings 86."l It will be readily 'seen that the eccentric bearing 42 and the eccentric bearing 43 are continually oiled and cooled during the operation of the mill.

The outboard bearing 44 is an oil sealed bearing having a rollway 94 operating within oil contained in chamber 95 the oil being sealed within chamber 95 by oil seal flanges 96 supporting oil seal rings 97.

Mills of this character heretofore em-y ployed beveled gearing for driving the rolls. Considerable difficulty was experienced in providing a smooth running mill because of the play between the bevel gears which was considerable because of the large sized gears. Furthermore such mills were extremely noisy in operation due to the large gear teeth meshing with each other. By providing a worm drive described a smooth running mill has been obtained which is so constructed that it can be easily assembled and constituted of few parts. By forming the supporting casing for the worm gear and worm with its shaft in one integral casting it is possible to do away with separate castings which require machining and fitting. By placing the bearings for the worm shaft in eccentrics the worm .and gear can be assembled or removed with ease also making it possible to cast the worm shaft casing integral with the worm gear casing.

The shaft 19 at its lower end rotates in the steadying bearing 98 supported in upright 99 bolted to the base 11 by bolts 100. The bearing support 41 provides a mounting for the main shaft bearing 101 and thrust bearing 102 which supports the weight of the rolls 15 and their supporting structures through worm gear 23 which is secured to shaft 19 by nut 103 locked by screw bolts 104.

Obviously the present invention is not limited to the details of the illustrated embodiment of the invention herein shown and described. Moreover, it is not indispensable that all the features of the invention be used conjointly since they may be employed advantageously in various combinations and sub-combinations.

Having described one embodiment of the invention, I claim 1. In a grinding mill having a base, a vertical shaft, a worm gear for actuating said shaft, a worm, a shaft for said worm,l ,a supporting frame consisting of two uprights mounted on said base and an overhead supporting structure connecting said uprights forming an integral supporting gear casing for said worm gear, worm and worm shaft, eccentric bearing supports for said woim shaft Within said gear casing, cooling means for said eccentric bearing supports, bearings for said worm shaft within said bearing supports, and means for circulating oil through said bearings.

2. In a grinding mill having a base, a vertical shaft, a Worin gear for actuating said shaft, a worm, a shaft for said Worm, a supporting frame consisting of two uprights mounted on said base .and an overhead supporting structure connecting said uprights forming an integral supporting gear casing for said worm gear, worm and worm shaft, eccentric bearing supports for said worm shaft within said gear casing, cooling means for said eccentric bearing supports, bearings for said Worm shaft within said bearing supports and means for circulating oil contained in said gear casing through said bearings.

3. In a grinding mill having a base, a vertical shaft, a worm gear for actuating said shaft, a worm, a shaft for said worm, a supporting frame consisting of two uprights mounted on said base and an overhead supporting structure connecting said uprights forming a-supporting gear casing for said worm gear, worm and worm shaft, eccentric bearing supports within said gear casing for said worm shaft, an outboard bearing for said worm shaft and an outboard bearing support connecting said outboard bearing with said supporting frame adapted to niove longitudinally upon eccentric movement of said eccentric bearing supports.

4. A grinding mill having a drive shaft, bearings for said shaft, eccentric supports for said bearings having a longitudinal water circulating passage therein, a thrust bearing on one end of said shaft, a thrust bearing support having a circulating water passage communicating with the Water passage in said eccentric bearing support for cooling said bearing.

5. In a grinding mill having a drive shaft, a bearing adjacent one end of said shaft and eccentric bearing support for said bearing having a water circulating passage substantially twice as long as said bearing support, a thrust bearing on the end of said shaft, a thrust bearing support having a water circulating passage and a thrust bearing seat between said eccentric bearing support and said thrust bearing support having a circulating water passage, said water passage communicating with each other so that the flow of water passes through the length of the eccentric bearing support twice through the thrust bearing seat and completely around the thrust bearing support.

CHARLES E. NEEDHAM. 

